YD Series pole changing Induction motor is a pole-changing adjustable speed motor which changes the winding connection type to change its speed and power. It belongs to step speed regulation motor. This series motor adopts the method of pole changing in a single winding to achieve speed regulation, including two speeds and three speeds. It has features of wide range of use, good starting performance, reliable operation and easy maintenance. Etc. These series motors apply to all kinds of machinery which need step speed regulation (not suitable for fan blowers and pumps). It has features of simple structure, small volume, low noise and low price.